This invention relates to measurement devices, and more particularly to a level detector for measuring the level of a material in a container.
Level detection is used in a vast number of applications. High level detectors have special importance for a number of economic and safety reasons. For example, domestic liquid-propane (xe2x80x9cLPxe2x80x9d) gas tanks should not be filled above ninety percent of tank capacity, because heat can raise the pressure inside the tank to dangerous levels.
When filling an LP gas tank, an operator opens a valve at the top of the tank and fills the tank until the valve emits gas in liquid form. This is because the valve is connected to a tube with such a length that only liquid gas can be released when ninety percent of capacity is reached. This process can send polluting gas into the atmosphere thereby endangering the operators and anyone else nearby.
Level detection within tanks of fuels like gasoline oil and liquefied gas can be difficult using electric properties of these fuels because of their high electrical impedance. Furthermore, float sensors are difficult to use because of the erratic movement of the waves generated while filling the tank with these materials.
The present invention provides a level detector and method of level detection for materials contained in tanks that substantially eliminates or reduces at least some of the disadvantages and problems associated with the previous level detectors and methods.
In accordance with a particular embodiment of the present invention, a level detector is provided. The level detector includes a rod probe for positioning at least partially within a container suitable for containing a material. The rod probe has first and second ends. A monitoring device is coupled with the first end of the rod probe. The monitoring device is operable to produce a reading when a ground connector contacts the monitoring device. The reading is based upon whether the second end of the rod probe contacts the material. The reading may also be based upon an electrical impedance of the material when the second end of the rod probe contacts the material. The ground connector may be a person.
In accordance with another embodiment, a level detector is provided. The level detector includes a rod probe for positioning at least partially within a container suitable for containing a material. The rod probe has first and second ends. A monitoring device is coupled with the first end of the rod probe. The monitoring device includes at least part of a circuit. The circuit has a frequency. The monitoring device is operable to produce a reading when a ground connector contacts the monitoring device. The reading is related to the frequency of the circuit. The frequency may be related to an electrical impedance of the circuit.
Technical advantages of particular embodiments of the present invention include a level detector that displays a reading enabling a user to determine when a material is filled to a particular level within a container. Accordingly, overfilling the container to determine when the container is full of the material is unnecessary.
Another technical advantage of particular embodiments of the present invention includes a level detector that produces a frequency based upon the electrical impedance of the material in the container. Accordingly, a user can determine the type of material in the container based upon the frequency produced by the level detector. Furthermore, a user may be able to determine if there are contaminant materials in the container.
Another technical advantage of particular embodiments of the present invention includes a level detector which uses a rod probe positioned partially within the container to detect the level of the material in the container. Accordingly, installation is less difficult and does not require a wide orifice as a float sensor may require.
Another technical advantage of particular embodiments of the preset invention includes a level detector with a circuit that uses a person as a ground connection to begin current flow through the circuit. Accordingly, less components are needed to operate the level detector.
Other technical advantages will be readily apparent to one skilled in the art from the following figures, descriptions and claims. Moreover, while specific advantages have been enumerated above, various embodiments may include all, some or none of the enumerated advantages.